Surgical procedures for replacing a crystalline lens of a human eye are well known. To practice such procedures, typically an incision is made in a patient's cornea or sclera, and an opening is made in the anterior portion of the capsular bag which surrounds the patient's lens. Such an opening is commonly referred to as a “capsularhexis” (or simply as a “rhexis”); and the process by which the opening is made is commonly referred to as a “capsulotomy.” After the opening is made, the eye's lens is removed through the rhexis and a replacement lens (referred to herein as an intraocular lens (or an IOL)) is inserted into the capsular bag through the rhexis.
According to conventional procedures, the incision in the cornea is made with a scalpel, and a pointed stylet or needle is inserted through the incision and is used to rip or tear a generally circular rhexis into the anterior capsular bag.
The use of such a stylet or needle to tear an opening in the anterior capsular bag requires a steady hand and a very high degree of skill. Even when practiced by a skilled surgeon, the potential for incorrectly performing the procedure is substantial.
Forming a rhexis having a larger or smaller diameter than that desired, or inadvertently tearing the capsular bag may prevent the remaining capsular bag from properly retaining an IOL and may result in complications, including infection, damage to other portions of the eye, and potential loss of sight.
As such, although conventional capsulotomy procedures have proven generally suitable for lens replacement surgery, it has deficiencies which may detract substantially from its safety and efficacy. In view of these shortcomings, it is highly desirable to provide a means for reliably and safely forming a rhexis of a desired diameter and shape.